Active Mode Power Management for Mobile Devices

As computer technology becomes more miniaturized and mobile, power management becomes an everincreasing concern to users wanting freedom from conventional power supplies, yet full access to data while roaming. Mobile connectivity is fully available, but at the precious price of increased energy consumption. This increased energy consumption reduces mobility, requiring frequent, undesired recharge sessions. Current power management techniques revolve around the lower layers of the protocol stack. This approach treats all applications equally and leaves the burden of choosing the best power management settings with the user. But different applications require different levels of connectivity, and thus different energy requirements. Mobile devices such as the Personal Data Assistant (PDA), PocketPC, or mobile laptop, and the applications they support, cannot afford to be treated equally. This paper explores the idea of migrating power management to a much higher level - the application layer. The key is to take as much information as possible from the applications that require connectivity and allow them to directly and dynamically control applicable power management techniques. Active Mode Power Management (AM/PM) can take advantage of today's modular languages through the use of Application Protocol Interfaces (APIs). This paper looks at the plausibility of such API-based power management software and provides benchmarktesting figures to substantiate its validity. Power usage data, from a mobile device equipped with an IEEE 802.11b wireless LAN PC card, are presented. KEYWORDS: Mobile Computing, Active Mode Power Management